Space Exploration Crossword Challenge

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Across
  1. 1. - Small rock or particle in space (9 letters).
  2. 5. - Trained to travel and work in space (9 letters).
  3. 6. - A region in space where gravity is so strong that nothing can escape it (9 letters).
  4. 8. - Instrument for observing distant objects in space (9 letters).
Down
  1. 2. - The path an object takes around another in space (5 letters).
  2. 3. - Vast system of stars, gas, dust, and dark matter (7 letters).
  3. 4. - Artificial object orbiting a planet for various purposes (9 letters).
  4. 7. - Celestial body with a tail, often visible from Earth (5 letters).